Examine Race/Ethnicity Disparities in Perception, Intention, and Screening of Dementia in a Community Setting: Scoping Review

Background: Delayed detection and diagnosis of Alzheimer’s Disease and related dementia (ADRD) can lead to suboptimal care and socioeconomic burdens on individuals, families, and communities. Our objective is to investigate dementia screening behavior focusing on minority older populations and assess whether there are ethnic differences in ADRD screening behavior. Methods: The scoping review method was utilized to examine ADRD screening behavior and contributing factors for missed and delayed screening/diagnosis focusing on race/ethnicity. Results: 2288 papers were identified, of which 21 met the inclusion criteria. We identified six dimensions of ADRD screening behavior: Noticing Symptoms, Recognizing a problem, Accepting Screen, Intending Screen, Action, and Integrating with time. Final findings were organized into study race/ethnicity, theoretical background, the methods of quantitative and qualitative studies, description and measures of ADRD screening behavior, and racial/ethnic differences in ADRD screening behavior. Conclusions: A trend in ethnic disparities in screening for ADRD was observed. Our findings point to the fact that there is a scarcity of studies focusing on describing ethnic-specific ADRD screening behavior as well as a lack of those examining the impact of ethnicity on ADRD screening behavior, especially studies where Asian Americans are almost invisible.


Introduction
According to an annual report of the Alzheimer's Association, more than six million Americans live with Alzheimer's disease and related dementia (ADRD). Between 2000 and 2019, one in three seniors died from ADRD, while the number of deaths from heart disease decreased by 7.3% [1]. Currently, more than 55 million people live with dementia globally, and there are nearly 10 million new cases every year. The magnitude of health economics and the human and social impact on individuals living with dementia, their families, communities, and society are drastically increasing. It is estimated that the global cost of dementia could grow to US$2 trillion by 2030.
Although there are currently no specific treatments to block the progression of cognitive decline in ADRD, an early diagnosis helps patients and families to plan for their future care and treatment. However, dementia is substantially underdiagnosed by clinicians and underreported by patients and families in the U.S., and studies have found that 40 percent to more than half of patients with dementia had not received a clinical cognitive evaluation by a physician [2][3][4]. Moreover, according to Healthy People 2020, baseline data show that, even among those diagnosed with dementia, nearly two-thirds of them or their caregivers were aware of the diagnosis [5]. Studies show that racial/ethnic disparities in misdiagnosis and the problem of underdiagnosis are even more pronounced in underserved populations and those with low socioeconomic status (SES) [6][7][8][9][10][11]. In the same vein, evidence points to the fact that, at first dementia diagnosis, racial/ethnic minorities are more impaired and show more severe clinical symptoms, which may suggest that diagnosis occurs at a later stage of the disease for these groups [12,13]. The older population is becoming more racially and ethnically diverse. Between 2014 and 2060, the share of the older non-Hispanic white population is projected to drop by 24 percentage points, from 78.3 percent to 54.6 percent, in the U.S.; therefore, a higher percentage of people with ADRD will be minorities [14]. The literature supports the need for studies exploring and explaining the impact of the ethnoracial factors on ADRD, not only genetic and biological factors, but also sociocultural factors related to the timing of diagnosis, lay symptom recognition, lay diagnosis and course of AD between different ethnocidal groups [15,16].
Differences in dementia screening behavior from both healthcare professionals and patients or patient families can be expected as a function of the ethnoracial factors because the ethnoracial groups are characterized by distinct social and behavioral practices [16,17]. Several factors related to dementia screening and diagnosis, including the individual level of health belief, sociocultural norms, and access to healthcare services among elderly minority populations, pose special challenges in dementia diagnosis and treatment [16][17][18][19][20][21]. However, there is scarce information on the extent of understanding dementia screening behavior among ethnic minorities. Understanding dementia screening behavior and race/ethnicity as influencing the proportion of detected and undetected dementia is important for improving dementia screening/diagnosing behaviors and moving to equity of ADRD management.
This review aims to investigate dementia screening behavior among minority older populations and whether there are any racial/ethnic differences in screening behaviors. Thus, we only reviewed studies that addressed ADRD screening/diagnosing behavior among ethnic/racial minorities in North America versus reports of screening/diagnosis rates.

Materials and Methods
We adopted the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews (PRISMA-ScR) [22]. A scoping review uses systematic and rigorous methods and summarizes the findings from the body of knowledge that is heterogeneous in methods including both quantitative and qualitative designs or disciplines [22][23][24][25][26][27]. The difference from a systematic review is that a scoping review does not have a specific research question, but rather seeks to provide a broad overview of the available literature and identify gaps in the literature [24,26]. Our protocol was drafted using both PRISMA-ScR and Arksey and O'Malley's scoping review guidelines [22][23][24][25]. No ethical approval is required for this type of study.

Search Strategy and Study Selection
The search strategy included databases, search terms, and inclusion/exclusion criteria. Three databases (PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and PsycINFO) were used to search for the most relevant literature. Search terms to find published studies that reported on factors associated with dementia screening behaviors were determined through several discussions with a university librarian: "dementia screening", "Alzheimer's disease screening", "barriers", "delayed", "facilitators", factors", "pathway", "race", "ethnicity", "minorities", "Asian American", "Black/African American", "Hispanic", "Latino/a", and "Native American", combined with the Boolean operator "AND/OR." The publication year of the literature was restricted from 2000 onwards because the number of deaths from Alzheimer's disease (AD) has increased by more than 145% from 2000 to 2019 in the U.S. [1]. One of the authors (H.L.) who designed this study recommended several studies of examples that might be included in the literature. An additional database search for more studies targeting Asian Americans was conducted. For this search, the university librarian designed additional search terms as follows: "Chinese American", "Filipino American", "Asian Indian American", "Korean American", "Vietnamese American", and "Japanese American", which are the five largest Asian American subgroups.
Prior to the initiation of screening, duplicate records were removed. After duplicates were removed, articles retrieved from the databases and the author's recommendations were screened for their titles, abstracts, and full texts to determine their eligibility. Only empirical articles with an English abstract were included. Since the aim of the scoping review is to provide a broad overview of relevant studies, we considered all types of research design. We applied the following inclusion criteria at two stages of study selection (screening by title and abstract, and then full text). Inclusion criteria involved: (a) use of primary data reporting factors relative to ADRD screening behaviors, (b) conducted in North America (the U.S. or Canada), (c) covering the older adult population, (d) published in English, and (e) full text available. Excluded criteria were studies: (a) focused on countries outside North America, (b) did not measure ADRD screening behavior, and (c) did not report any data for minority populations as this study sought to examine dementia screening behavior among the ethnic minority older adult population and there are any disparities in dementia screening.
To increase consistency among reviewers, three researchers (H.L., S.L., D.K.) independently performed screening by assigning studies to "include," "exclude," or "not sure" categories and discussed the results. Discrepancies among researchers were resolved through discussion, and the screening and data extraction guidance was revised.
Lastly, reference lists of included studies were hand searched and screened to ensure the complete inclusion of relevant studies. Final decisions about the inclusion of studies were made upon the discussion and agreement between researchers. Figure 1 presents the process diagram indicating the search process.

Data Extraction
Each full text of the included studies was critically assessed to extract data. Data were extracted using a standardized data extraction table that the research team developed, including (a) characteristics such as design, research setting, and ethnicity of participants, (b) theory or framework, (c) dementia screening behaviors, (d) measures, and (e) major

Data Extraction
Each full text of the included studies was critically assessed to extract data. Data were extracted using a standardized data extraction table that the research team developed, including (a) characteristics such as design, research setting, and ethnicity of participants, (b) theory or framework, (c) dementia screening behaviors, (d) measures, and (e) major findings and discussion. Three reviewers jointly developed a data-charting form to determine which variable to extract. The two reviewers (S.L. and D.K.) independently charted the data, discussed the results, and continuously updated the data charting in an interactive process. These data were extracted by two researchers (S.L. and D.K.) and then examined and agreed upon by the PI (H.L.) to ensure validity.

Collecting and Summarization
The scoping review findings of the literature are documented in Tables 1-3 in the narrative text. A descriptive-analytical method was utilized to present a narrative account of the existing literature. Data-charting tables were developed to sort the extracted data and included charting of key features. The tables include the geographical distribution of studies, research methods, dimensions and measures of screening behavior, race/ethnicity of participants, and major findings; the studies are listed in the chronological order of publication date, from the earliest to the most recent publication. Older age (>75 years) low education, and perceived problem with memory associated with screening positive but no effect from race and research sites.   [29] Intending Screen Intention or willingness undergo screen "No critical event either physical or cognitive symptoms to trigger their desire to seek care" "Concerns safety is cue" (Leung et al. 2011) [44] "Plan to screen for AD at some point in life" "Plan to screen for AD in the next year" "Plan to screen for AD after the participant reaches a certain age" "Plan to screen for AD in the presence of symptoms for AD" (Park et al. 2020) [36] Action Taking actions to assess the symptoms Diagnosis process was multiple visits and interactions with health professionals.   Prior diagnosis of dementia (weighted) 48% 41.1% † "Other" racial groups are also included in the reference group. ‡ No statistical significance. Abbreviations: OR, odds ratio; PR, prevalence ratio.

Search Results
The final articles about ADRD screening or diagnosis behavior, and factors associated with screening behavior were analyzed. The final articles were organized into study locations, designs, sampling, race/ethnicity and language, and major findings of dementia screening behavior (Table 1). In order to provide structure and meaning to the results, we created thematic frameworks [23]. Three frameworks were created including study characteristics, dimensions of ADRD screening behaviors, and ADRD screening behaviors by race/ethnicity. Table 1 presents the quantitative, mixed-methods, and qualitative studies. Among the quantitative studies, five studies used the existing national health survey data or Medicare/Medicaid data. No experimental studies were included. As can be seen by reviewing Table 1, most studies were cross-sectional surveys that were conducted in the U.S. Various qualitative methods were used, including open-ended interviews, focus groups, grounded theory, semi-structured and in-depth interviews, and ethnography. The studies took place in the U.S. (n = 17) and Canada (n = 4). Race/ethnicities studied were: (1) Whites; (2) Blacks; (3) Hispanics; (4) Asian Americans; (5) Native Americans; and (6) others. Subgroups of Blacks were African Americans and Caribbean Blacks, subgroups of Whites were non-Hispanic Whites and French-speaking Whites, and subgroups of Asian Americans were Chinese, Korean, South Asian, Indian, and Sri Lankan.

Sample Characteristics
The most frequently studied ethnic group was Blacks (n = 14), followed by Asians (n = 7) and non-white Latinos (n = 6) ethnic groups. Two studies covered Native Americans [34,36]. All areas, urban (n = 11), suburban (n = 4), and rural (n = 4), were included. Fourteen papers studied patients or people with and without dementia in their research. Nine papers involved only patients, and five studies involved both patients and family caregivers as dyads. Patients with or without dementia were the largest group of participants in the identified studies. In terms of settings of the studies, 17 studies were conducted in the U.S., and four in Canada. Subjects were recruited from clinics, community-based clinics, or community organizations. All primary quantitative studies recruited the participants in person through the partner agencies' networks, phone calls, advertising materials (e.g., flyers, newspapers, and social media). Five studies utilized the existing population-based national data about health insurance (e.g., the National Health and Aging Trends Study (NHATS) and California Medicare fee-for-service data) or older adults' economic, health, and psychosocial information (e.g., the Health and Retirement Study (HRS)). Of the five, three studies utilized a combination of in-person and online recruitment methods such as email [39,40] and social media [33]. Potential participants were recruited by referral from local community centers, physician offices, churches, senior centers, and memory disorder clinics. Only two studies [32,35] included a report of the response rate, and one study [35] included a report of response rates below 7.5%. As this study focused on North America, most studies (n = 12) used English, except for seven studies without language information for the recruitment or data collection. Of the 12, five studies reported "English-speaking" as an inclusion criterion. Seven studies used both English and other minorities' languages, such as Spanish (n = 4), Korean (n = 1), Chinese (n = 1), and Hindi (n = 1). Two studies used only the language of their target population, French or Chinese.

Theoretical Trends
Most quantitative studies were conducted without theoretical frameworks. Only two cross-sectional studies [33,36] used theoretical frameworks: a modified version of the Integrated Behavior Model [36], and a conceptual framework were developed based on the attitude theories focusing on stigma beliefs and subjective norms of AD care among Korean Americans [33]. Two qualitative [43,45] and one mixed-methods [39] studies used health belief models or a health-seeking model to explore the perception of dementia screening and to explain the rationale for dementia screening-seeking behaviors among ethnically diverse patients, family caregivers, and stakeholders. According to the Kaleidoscope Model of Health Communication, Garcia and others' study [47] looked at health communication between HCPs and French-speaking patients, especially people with dementia who reverted to their primary languages among Francophones.

ADRD Screening Behavior Is A Multidimensional Construct
We have found that two terms of AD and dementia are often used interchangeably in the study and practice; however, AD is preferred more than dementia because patients more readily understand the term [30]. Hence, the term ADRD screening behavior will be used in this paper for dementia and AD screening behavior. The literature revealed that ADRD screening behavior is a multidimensional construct including both subjective perception and objective screening action, specifically, dimensions of noticing symptoms, recognizing a problem, accepting screen, intending to screen, action, and integrating with time ( Table 2). ADRD screening behavior is integrated with time as it is defined as delayed, timely, or early screenings. Most studies focused on recognition of the problem (n = 6), acceptance or intention (n = 4) to do screening of ADRD, and actual ADRD screening (n = 4). The empirical statements for each dimension extracted from the included studies were summarized and are compared in Table 2.
Though the phenomenon of ADRD screening behavior is on a continuum, and it is not static, most quantitative studies utilized cross-sectional design and typically examined associations between screening behavior and its correlates as static. Qualitative [42][43][44][45][46][47] studies addressed that dementia screening behavior is not static and that it is fluid, and screening pathways which were multiple stages of the screening process were identified by examining and reporting recognition of dementia symptoms, making lay diagnosis or awareness of the problem, intention to screening, and then taking screening examinations. However, some people can move back and forth along the pathways. Koehn and others [45] stated that most Chinese Canadian caregivers described a process of gradually piecing together the rationale to explain their spouses' or parents' "puzzling behaviors", and Leung and others [44] described that none of the Euro-Canadian participants identified any critical event, but rather a gradual memory decline when asked what triggered their desire to seek care. However, once Chinese Canadian caregivers realized that the symptoms and behaviors were "problematic", they quickly sought additional information, usually from a family physician [45].
As for measurements, there is limited information assessing the multidimensional and time-bounded pheromone of ADRD seeking behavior. There is an absence of a commonly agreed-upon approach to assess ADRD seeking behavior, as shown in Table 2. In general, dementia screening behaviors were measured based on a focus on the types of dimensions of the construct of screening behavior that they were interested in studying (Table 2). Most measures were developed by authors for their studies or revised the existing tools which measured similar concepts [29,31,33,36,39]. For instance, the PRISM-PC questionnaire, which is most often used [30,31,39,40], consists of two separate scales: the patient's acceptance of the dementia screening scale and the patient's perceived harms and benefits of the dementia screening scale. The measure of action included both whether ADRD screening/diagnosis was missed or delayed [37], or screened/diagnosed ADRD involved the use of clinical interviews and previously standardized and/or validated assessment criteria [7,34,35,38]. Missed/delayed screening/diagnosis were usually assessed using the proportion of patients or people within the research settings who were considered to have ADRD but who were not diagnosed by their physicians or had no information in their medical records. Five of 17 quantitative studies used the existing population-based data in conjunction with Medicare and Medicaid data [7,32,34,37,38]. Regarding screening behavior integrated with timing, the interval was measured from noticing or recognition of symptoms of dementia either by patients, caregivers, or HCPs to first contacting a physician or actual screening. The term "Delay" is often used to report the intervals that were reported in days or months and categorized into two delays: delay before recognizing the problem of symptoms and delay before patients or caregivers contact physicians [28]. The time interval or delay was measured in months, and reported delay times before recognizing problems of symptoms and before physician consultation was 0 to 84 months and 0.1 to 84 months, respectively [28].

Differences in ADRD Screening Behavior among Ethnicities
We first provide comparative summaries on awareness, intention, and action of screening and diagnosis among minority ethnic groups (Table 3). We then summarize the quantitative reports about African Americans/Blacks, Hispanics/Latinos, and Asian American groups. Several studies either reported on individual ethnic groups, in aggregate or multiple ethnic groups. The majority of studies reported that minority groups had low awareness, intention, and diagnosis, compared to non-Hispanic White reference groups [7,31,37,41]. Differences between minority ethnic groups were more evident from population-based research than from clinic-based or community-based studies (Tables 1 and 3). For example, Gianattasio et al. [7] reported that Blacks had double the risk of being underdiagnosed com- Asians (incidence RR = 0.81; 95% CI = 0.74-0.87) also received fewer diagnostic evaluations, and these associations remained significant after adjusting for age, sex, comorbidity burden, neighborhood disadvantage, and rurality.
Among six qualitative studies, four were reported from Canada, of which three reported on Chinese, South Asian, and French-speaking groups [45][46][47]. Most qualitative studies explored experiences in the perception of noticing symptoms and how recognizing symptoms as problematic translated into making a lay diagnosis to seek medical attention from patients, family, and stakeholders. Though there are multiple pathways of the screening process from noticing symptoms to having been screened, no ethnic-specific pathways were reported. Rather, there is a general trend that, at the first notice of symptoms, most participants, regardless of their ethnicity and whether they are patients or family members, considered it as a normal aging process or temporary episodes. However, among Chinese, South Asian, and French-Canadian subgroups, themes of cultural communication emerged and were linked with delayed diagnosis. The following quotes illustrate the point: "He recalls that his mother's doctor, who practices in Chinatown, said, 'don't expect too much . . . it is like a machine. After a long period of time, its parts will certainly be off or fall apart.' The son denies that his mother has ever received a formal diagnosis of AD or dementia. He wishes that the doctor would 'explain more' and emphasized language barriers as a significant problem in getting care for his mother." [42] (p. 140) In another study, they pointed to the fact that they would like to have physicians who speak the same ethnic language even though they speak English. "He (patient) lost a lot of his English . . . we had settled down for good . . . , there was the possibility of getting a doctor in French" [47] (p. 972). They were waiting for a physician who could communicate in French, which is one of the reasons for the delay in screening. In addition, in the Asian, Chinese subgroup, a stigma theme emerged: "I think my family did not have this before. I thought that when people got old, they would be forgetful, talked silly and sometimes insane. It is not a disease, but a natural course of life . . . because in old age, it is like that -it should be crazy (Shu*)" [45] (p. 49).

Discussion
With no effective treatment to prevent or modify the disease course, AD is an immense burden on our economy, patients, and caregivers; hence, early screening of ADRD based on early recognition of the problem of symptoms and caregivers' concerns is critical to identify reversible etiologies and reduce patient and caregiver burden. This paper has performed a scope literature review of ADRD screening behavior focusing on ethnic minorities in North America since the racial/ethnicity factors that contribute to screening behavior are not well understood. The results point to the fact that there is a scarcity of studies focusing on describing ethnic-specific ADRD screening behavior as well as a lack of those examining the impact of ethnicities on ADRD screening behavior; especially, studies with Asian Americans are almost invisible. Although Asian Americans are the fastest-growing population in the U.S., ADRD research on Asian Americans is limited. It is reported that clinical research focused on Asian Americans and funded by the NIH only comprised 0.17% of its total budget based on 529 projects [48]. Although the goals of the 2012 National Plan to Address AD include strategies to diversify outreach in AD research [49], as observed in this review, investment and data for AD research on Asian Americans remain insufficient. As the incidence of ADRD increases significantly with age, especially among racial and ethnic minority groups, the fastest-growing population in the U.S., we believe our findings are very timely to exhort health policymakers and the scientific community to conduct more studies to enhance our understanding of this underserved and understudied population.
The most common first signs and symptoms noticed by the patient or others were memory loss, repeated questions, or word-finding problems, and the common cues to a willingness to screen were concerns about safety for patients, others, and the environment. These results are in agreement with two previous systematic literature reviews of nonethnic group selected studies [17,20], suggesting that the association of concern about the safety of patients with prompting them to seek screening is generalizable. A lack of awareness, misunderstanding, access to healthcare resources, and stigma around ADRD combined with few treatment options are barriers to ADRD screening behavior. However, this conclusion could be incomplete due to the relatively small numbers of papers with heterogeneous designs with diverse racial/ethnic groups.
More racial and ethnic minorities were not aware of their cognitive symptoms, not talking to their HCP about their problems, were not being diagnosed, or among patients who were diagnosed, their family members were not informed by HCPs. These results align with previous findings from systemic literature reviews [50,51]. Both patients and caregivers emphasized that there were accumulated symptoms including memory prob-lems, repeated questions, and a decline in judgment including handling checks and bank accounts, which implies that those symptoms could not be related to a single event. Previous literature has pointed out that non-ethnically matched HCPs' misinterpretations of cultural behaviors might cause delayed diagnosis or misdiagnosis [52]. However, we did not find a positive impact of ethnically matched patients and HCPs on timely screening and cultural communication with caregivers from qualitative studies, which might be due to diversity within the racial/ethnic populations in North America. However, this finding suggests that HCPs will encounter more culturally diverse patients and there is no textbook for this encounter, but there is a need to study qualitatively and quantitatively racially and culturally diverse groups.

Strengths and Limitations
We included many search terms related to race/ethnicity and included both quantitative and qualitative methods. However, we only included studies conducted in North America and reviewed articles studying racial/ethnic minorities. The fact that only a few studies investigated Asian Americans in our report might be due to our decision to include only peer-reviewed articles. This review did not assess the methodological quality of the included studies as we reviewed both qualitative and quantitative methodologies. However, we think that this body of systematic scoping reviews provides important information that ADRD screening behavior is a multidimensional phenomenon, and it is not static but changes along the continuum of racial/ethnic minorities and that there is a lack of race/ethnicity-specific research, especially among immigrant minority populations. Health care and health research related to ADRD for immigrants is particularly challenging with the triple factors of low health literacy, cultural differences, and limited English proficiency [53], which would act as barriers to an effective screening of ADRD. As well, their impact on recruitment and how research is conducted should be addressed in health policy and research priority settings.
ADRD screening behavior in diverse populations may also be influenced by other sociodemographic factors including educational level, healthcare access, and relationships with healthcare professionals [26,32,33,35,40,42,47,[53][54][55][56][57][58][59]. These factors might moderate the relationship between race/ethnicity and ADRD screening seeking behavior. For example, differences in educational attainment may account for the race-specific variability in screening seeking behavior [26,33,40]. Despite near-universal healthcare coverage through Medicare for seniors in the U.S, there are consistent reports of financial barriers to healthcare access, especially among racial/ethnic minority elders in the U.S. compared to Canada and other European countries [53,54]. In addition, racial/ethnic minorities may also have different perceptions and attitudes toward ADRD screening procedures than their White counterparts [55][56][57][58][59]. There exists evidence that Black adults mistrust the healthcare system and White healthcare providers because of a history of mistreatment as well as consistent racial disparities in health and health care [58][59][60]. Mistrust of healthcare providers or the healthcare system and being unable to communicate clearly with healthcare providers about their symptoms of dementia which are culturally bounded may lead to a great impact on ADRD screening seeking behavior. Exploring these sociocultural factors related to ADRD screening seeking behavior across cultures is a promising avenue for future research and we should pay more attention to addressing this problem.
Given that this review focused on studies conducted in the U.S. (English) and Canada (English/French), the language barrier is considered one of the main barriers to ADRD screening behavior in these monolingual countries. However, this observation might differ from countries where multiple languages are commonly spoken (e.g., in several European countries). Thus, our focus on the healthcare context in U.S. and Canada might limit the generalizability of our results.

Conclusions
A trend in ethnic disparities in screening for ADRD was observed. Timely detection of dementia is equally important as well as knowing the neuropathophysiological diagnosis. However, our findings point to the fact that there is a scarcity of studies focusing on describing ethnic-specific ADRD screening behavior as well as a lack of those examining the impact of ethnicity on ADRD screening behavior, especially studies where Asian Americans are almost invisible. We hope this article will ignite further inquiries to address how and what race-ethnic-related sociocultural factors such as education, healthcare access, health communication, and trusted healthcare providers have an influence on ADRD screening behavior and will impact health researchers, health policy makers, health practitioners, and stakeholders to be aware and to address the problems of ADRD screening seeking behaviors, especially among underserved and understudied racial-ethnic minority populations.

Institutional Review Board Statement:
The study did not require ethical approval.